You are a funny guy. I was hoping you'd fall prey to my infinite loop trap but you were too clever.
I swapped out hdd's and installed Windows XP Pro, installed all "critical" updates, the latest nVidia driver from their site, Far Cry, Oblivion, and patched both games with the most recent update. Both games after about five minutes of play briefly froze and appeared to swap large blocks of vram. This happened several more times until the game froze completely, after which Windows reported the NV driver had an error. I rebooted and was able to recreate the problem. I know my RAM, BIOS, and PCIe slot are fine, so it looks like some asshole on ebay tried to pull a fast one on me. I'm speaking to XFX customer support about their warranty/RMA policy so hopefully they'll take care of it.
I have another problem though, why does this eventually crash when I run it in GWBASIC? I can't figure it out and it's driving me crazy. If I can figure it out I'm going to move up to QuickBASIC 4.5, I hear it's the bomb.
100 print "Hello World!!!"
110 gosub 100
Thanks all.